Field of Invention
This invention relates generally to composting or the decomposition of organic waste material and, more particularly, to an improved composting method using both aerobic and anaerobic processes.
The process of composting or transforming organic waste materials into natural fertilizers and/or soil additives is well-known to those skilled in the art. Organic waste materials can be composted either aerobically i.e. with air or, in the alternative, anaerobically i.e. without air.
In order for the composting process to provide optimal results, certain conditions must exist. For example, the micro-organisms which decompose the organic waste material require an environment with adequate amounts of air, water, and nutrients to support metabolic activity. In the case of aerobic composting, the ambient air is the primary source of oxygen. Thus, the circulation of ambient air within the compost pile must be sufficient to meet the metabolic requirements of the microbes as well as to disperse the waste gases including methane gas which are produced as a by-product of the process.
In addition, aerobic composting is affected by the moisture content of the organic materials. Thus, if the water content of the organic material is too high, the aerobic microbes will be killed off and only the slower process of anaerobic decomposition will proceed.
Conversely, if the moisture of the decaying materials is too low, the composting microbes will not survive. Consequently, the water and air content of the composted materials must be maintained within a certain range to provide the best results.
Composting proceeds most efficiently within a certain temperature range as with the case of any chemical reaction. Aerobic composting is accelerated if the compost pile is insulated such that the heat generated by the decaying process is contained within the compost pile. However, once the internal temperature of the organic material mass exceeds the desired temperature range for any length of time, the aerobic microbes are killed off and only slower anaerobic composting will take place. As a rule the gaseous by-products of anaerobic composting tend to be foul smelling and to pollute the environment.
Thus, the present method combines both aerobic and anaerobic composting methods which transforms organic waste materials into a nutrient rich soil additive and fertilizer and reduces the odor associated with the anaerobic process.